1. Field of the Invention
The present invention relates to an image processing apparatus capable of extracting frame image data from video data and a method for controlling the same.
2. Description of the Related Art
Now, video data is variously used. For example, video data is displayed on a display unit by normally reproducing them, or frame image data is extracted from video data at any timing and image data to be displayed on a display unit or printed is generated from the extracted frame image data.
Japanese Patent Application Laid-Open No. 2003-333568 discusses a technique in which a low-resolution moving image is generated from a high-resolution moving image, and when clipping of a still image is instructed while the generated low-resolution moving image is viewed, the still image is clipped from the high-resolution moving image at a specified timing.
Recently, however, a plurality of video data different in field of view has been distributed. The field of view refers to the field of video data. The term field of view is also similarly used as expression corresponding to a field in computer graphics or animations, which are not image captured by a camera. For this reason, video large in field of view or video wide in field of view refer to video in which a wide area is captured or represented.
Suppose that, in a football (soccer) match, for example, there are two video images capturing the whole football stadium and only one football player in a football ground, which is a part of the whole football stadium. In this case, the video capturing the whole football stadium is the one that is wide in field of view and, on the other hand, the video capturing only one football player included in the video area wide in field of view is one that is narrow in field of view.
The video that is wide in field of view and the video that is narrow in field of view can be simultaneously distributed in parallel. Such a plurality videos can be different not only in field of view but also in the number of pixels in a frame image composing the video.
A case is assumed where frame image data is extracted from video data in situations where a plurality of videos different in field of view exists. A user displays the image data corresponding to any one field of view among a plurality of kinds of field of view, and gives an instruction about the extraction of a necessary frame image data while the video data is being displayed.
At this point, the frame image data extracted from the video data with another field of view which is not displayed by the user may be preferable for the user than the frame image data extracted from the displayed video data, which is the video data displayed by the user.
Suppose that, for example, there are two kinds of video data with a wide field of view capturing the whole football stadium and with a narrow field of view capturing one football player corresponding to a part of the field of view (area) in the video data. Furthermore, suppose that the video data with a narrow field of view is greater in the number of pixels per frame image and higher in pixel density than video data with a wide field of view.
If the technique discussed in Japanese Patent Application Laid-Open No. 2003-333568 is applied for the extraction of frame image data while the user displays video data with a narrow field of view, the frame image data is extracted from the image data which is greater in the number of pixels and higher in pixel density, i.e., from high-resolution video data with a narrow field of view than video data with a wide field of view.
Though the area not captured in the displayed video data with a narrow field of view is included in the video data with a wide field of view, which is not displayed, the user cannot acquire image data of the video data with a wide field of view. This is because the technique discussed in Japanese Patent Application Laid-Open No. 2003-333568 does not assume that the video data different in field of view exist.
Another case is considered in which the user extracts the frame image while displaying the video data small in the number of pixels in a case where there exists the video data that is great in the number of pixels per frame image and the video data that is small in the number of pixels among the video data with the same field of view to each other.
In this case, it is more desirable for the user to extract the frame image data from the video data that is great in the number of pixels, which is not displayed, rather than from the displayed video data. This is because the frame image data extracted from the video data that is great in the number of pixels is higher in fineness and, therefore, suited for the display and print of the image data, which offers the advantage that extends options for the process and print of the image data.